MicroRNAs (miRNA) mediate distinct gene regulatory pathways triggered by epidermal growth factor receptor (EGFR) activation, which occurs commonly in lung cancers with poor prognosis. In this study, we report the discovery and mechanistic characterization of the miRNA miR-7 as an oncogenic "oncomiR" and its role as a key mediator of EGFR signaling in lung cancer cells. EGFR activation or ectopic expression of Ras as well as c-Myc stimulated miR-7 expression in an extracellular signal-regulated kinase (ERK)-dependent manner, suggesting that EGFR induces miR-7 expression through a Ras/ERK/Myc pathway. In support of this likelihood, c-Myc bound to the miR-7 promoter and enhanced its activity. Ectopic miR-7 promoted cell growth and tumor formation in lung cancer cells, significantly increasing the mortality of nude mice hosts, which were orthotopically implanted with lung cancers. Quantitative proteomic analysis revealed that miR-7 decreased levels of the Ets2 transcriptional repression factor ERF, the coding sequence of which was found to contain a miR-7 complementary sequence. Indeed, ectopic miR-7 inhibited production of ERF messages with a wild-type but not a silently mutated coding sequence, and ectopic miR-7 rescued growth arrest produced by wild-type but not mutated ERF. Together, these results identified that ERF is a direct target of miR-7 in lung cancer. Our findings suggest that miR-7 may act as an important modulator of EGFRmediated oncogenesis, with potential applications as a novel prognostic biomarker and therapeutic target in lung cancer. Cancer Res; 70(21); 8822-31. ©2010 AACR.

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This study sets out to examine the relationship between both surgeon and hospital volume and five-year survival rates for breast cancer patients. We performed Cox proportional hazard regressions on a pooled population-based database linking the Taiwan National Health Insurance Research Database with the 'cause of death' data file, covering the three-year period from January 1997 to December 1999. Of the 13,360 breast cancer resection patients in our study sample, the five-year survival rates, by surgeon volume, were 77.3% in the high-volume group (>201 cases), 76.9% in the medium-volume group (45-200), and 69.5% in the low-volume group (585 cases), 74.5% for medium-volume hospitals (259-585) and 72.1% for low-volume hospitals (

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Tobacco-specific mitogen, nicotine, enhanced gastric cancer metastasis through alpha7-nAChR and suppression of E-cadherin level-one of the hallmarks of epithelial to mesenchymal transition. Therefore, patients with gastric cancer should avoid smoking.

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